Tiras, Keeper of Genesis [BP01-EN029] Starfoil Rare Spirit Monster discard all the cards in

discard all the cards in your hand

by Tributing 1 Thunder Effect non-Fusion Monster (in which case you do not use "Polymerization")

you can add 1 Counter Trap Card from your Graveyard to your hand

each time your opponent Special Summons a monster(s)

Tiras, Keeper of Genesis [BP01-EN029] Starfoil Rare Spirit Monster discard all the cards inSet: Battle Pack: Epic Dawn Card type: Xyz Effect Monster Rarity: Starfoil Rare Attack: 2600 Defense: 1700 2 Level 5 monsters. This card's effects can only be applied or activated while it has Xyz Material. This card cannot be destroyed by card effects. At the end of the Battle Phase, if this card attacked or was attacked: Target 1 card your opponent controls, destroy the target. During each of your End Phases: Detach 1 Xyz Material from this card.